CHAPTER 5 - Trigonometry: The Circular Functions
Publisher SummaryThis chapter provides an overview of trigonometry of the circular functions. From the definitions of trigonometry, it is understood that if t is real and W (t) = (x, y), then sin t = y, cos t = x, and tan . The domain of tan t is restricted so that x ≠ 0, that is, D: tan t = all reals except , where n is an integer. If a function, f (−x) = f (x), f is said to be even; on the other hand, if f (−x) = −f (−x), then f is said to be odd. A periodic function is one in which the function values repeat at a constant interval. The period of sin t and cos t is 2π. Both sin t and cos t show their periodic or wave nature by repeating y values at 2π intervals. The tangent function is also periodic, but its period is π. Composites of the trigonometric functions—for example, (1 − cos t) and (sin t + cos t)—can be graphed by adding the separate parts.
James W. Snow
Publication date: 1981/01/01